Distributed Renewable Energy Operating Impacts and Valuation Study

Section 2
Figure 2-7: Typical Spring-Day Residential PV System Output
March 25, 2007
kW AC
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
1 2 3 4 5 6 7 8 9 101112131415161718192021222324
Baseline (S-facing) E-Facing SE-Facing SW-Facing W-Facing
The summer data show that changing the orientation of the PV array shifts the hours in which
electric production takes place with no major impact on the peak rate of production for the day.
The spring data show a similar shifting of the production curve, but during this time period the
daily peak electric production is impacted by orientation. The south, southeast, and southwest
orientations have similar peak-day electric output while the east and west orientations produce
slightly less (approximately 94 and 90 percent of the daily peak production, respectively.)
Figures 2-8 and 2-9 show typical simulation results for commercial PV systems for the baseline
and various orientations for the same summer and spring days as the previous graphs. The
commercial results illustrate the impact of tilt (zero and 10 degree) and single-axis tracking. In
addition to the simulation results for the commercial PV systems, actual PV system production
from APS’s OPV2 and Solar Test and Research (STAR) Center facilities (as measured on the
right-hand axis in watts per square meter). Note that the PV model matches very well with
actual PV system production.
2-12 R. W. Beck, Inc. Arizona Public Service